Structural Neuroimaging of Hippocampus and Amygdala Subregions in Posttraumatic Stress Disorder: A Scoping Review
Ziv Ben‐Zion, Nachshon Korem, Naomi B. Fine, Sophia Katz, Megha Siddhanta, Melissa Funaro, Or Duek, Tobias R. Spiller, Sarah K. Danböck, Ifat Levy, Ilan Harpaz‐Rotem
Abstract
Numerous studies have explored the relationship between posttraumatic stress disorder (PTSD) and the hippocampus and the amygdala, as both regions are implicated in the disorder’s pathogenesis and pathophysiology. Nevertheless, those key limbic regions consist of functionally and cytoarchitecturally distinct substructures that may play a different role in the etiology of PTSD. Spurred by the availability of automatic segmentation software, structural neuroimaging studies of human hippocampal and amygdala subregions have proliferated in recent years. Here, we present a pre-registered scoping review of the existing structural neuroimaging studies of the hippocampus and amygdala subregions in adults diagnosed with PTSD. A total of n=3513 studies assessing subregions volumes were identified, n=1689 of which were screened, and n=21 studies were eligible for this review (total n=2876 individuals). Most studies examined hippocampal subregions and reported decreased CA1, CA3, dentate gyrus and subiculum volumes in PTSD. Fewer studies investigated amygdala subregions and reported altered lateral, basal, and central nuclei volumes in PTSD. This review further highlights the conceptual and methodological limitations of the current literature and identifies future directions to better understand the distinct roles of hippocampal and amygdalar subregions in post-traumatic psychopathology.